I may be a total idiot who just can't find his way around make menuconfig

No you are not !
fbcondecor is usually part of the genpatches extra and 3.7 no longer include these patches.
I've heard about some troubles with 3.7 and fbcondecor and that the maintainer of this patch was working on it.
So... could be back with future releases._________________

When I reed that Fbcondecor was retired from the Genpatches ('Remove incompatible fbcondecor patch' 0000_README), I try one time to patch manually the Gentoo-sources 3.7.0, with errors. Than I decided to remove anything related with Fbcondecor, splashutils, etc. Even with ArchLinux who have linux-fbcondecor package from AUR, who is working less well than Fbcondecor from Gentoo.

Ideally, Fbcondecor should be usable only in user space with no need to have source code in the Linux kernel tree. I do not think that the Linux kernel developers aim to integrate the Fbcondecor source code in the tree anyway. From user space mean too that you can use the initramfs possibility's to have a splashimage at early boot time without the need of kernel code.

A simple feature that is complicated to have out of X and that have nothing critical for the boot process with drawback of creating power management problems. White on black give the best readable console in practice.

Fbcondecor using the Splashy concept would be fine. I do not have enough expertise for it,